The reason for the 10x difference is that paper currency is used at least thousands of times more than bitcoin. Thus it's several orders of magnitude more efficient. Heck quite likely it's something like million times more efficient.
Moore's law doesn't help bitcoin. Because if we produce a miner that has 10x the power efficiency of a current mining hardware it just results into everyone using that miner. Total hashrate would be 10x but the electricity consumption would remain the same. The difficulty adjustment in bitcoin guarantees that regardless of the HW the profit from mining goes close to the electricity cost of it. Thus we can simply ignore Moore's law and focus on the fundamental point of bitcoin mining: Producing waste heat.
Having to continuously produce waste heat to secure the network is a fundamental flaw in bitcoin. An attack against the network (51% attack, using waste heat) must be sufficiently expensive compared to the gains of such an attack. The benefits of an attack scale with the amount of value transferred in bitcoin network. Thus the amount of waste heat constantly produced by honest people also must scale in order to keep it secure.
All of this because one person got the bright idea to solve Byzantine generals problem via unforgeable votes. What kind of vote is that? Waste heat. The guy just figured out how to verify that some other person has produced waste heat. And the whole network rests on the assumption that honest people buy more votes than the dishonest ones.
